Willow Pond CMAC

This large rain garden filters runoff and protects water quality in Bennett Lake.

This project involved the construction of a spent lime filter that takes intermittent flow from Willow Pond in Roseville through the use of continuous monitoring and adaptive control (CMAC) technology. Spent lime is a clay-like material used in municipal water treatment to remove tastes and odors in drinking water. The purpose of the filter is to clean water from Willow Pond before it travels downstream to Bennett Lake, which is impaired due to excess nutrients (especially phosphorus) that have run off of the surrounding land, including the outflow from Willow Pond. The system has multiple sensors that give real-time feedback to stop pumping when water drops below the minimum elevation.